1. Field of the Invention
This invention relates to a catch connection joining two drum components for a hydraulically actuated friction disc clutch of an automatic transmission for motor vehicles. In particular the invention pertains to the connection itself and to a technique for establishing and disestablishing it.
2. Description of the Prior Art
German Patentschrift 16 30 950 describes a technique for joining two drum components of a double clutch used to control gear ratio changes in a planetary gear system. The two drums are joined by a bayonet-type catch connection to form an assembled unit.
The bayonet-type catch connection makes it necessary to insert the two drum components axially into one another and thereafter to rotate one of them circumferentially with respect to the other. Furthermore, to prevent undesired release of the bayonet-type catch connection while the drum components rotate during operation, a push-over locking mechanism is provided to prevent relative rotation between the drum components.
The catch connection of the '950 document is therefore difficult to manipulate during assembly and requires additional cost to manufacture the locking mechanism.
A planetary gear transmission for motor vehicles is described in Patentschrift 20 13 612. The transmission includes two drum components of a hydraulically actuated double friction disc clutch connected mutually by interlocking the drum components to form an assembled unit. The interlocking is achieved by a snap ring groove provided on one component and a snap ring inserted within the groove and partially surrounding the other drum component. In this clutch, a carrier that supports one set of friction discs is supported by a thrust bearing on a cylindrical extension of a central carrier of the transmission. One drum component is rotatably mounted on the carrier by a radial needle bearing, from which the cylinder/piston unit is supplied with pressure from a source of hydraulic pressure.
Assembly and disassembly of the snap ring connecting the two drum components must be accomplished manually.